Let's Make Robots!

LMR series of PCB's

I think that LMR should have its own series of circuit boards, with the designs open source for all LMR'ians to use. Heres a couple ideas for PCB's:

  • SN754410 Board
  • Small Encoder boards
  • Various control boards for PIC, PICAXE, AVR, Arduino, etc

After finally getting a decent laser printer, i'm able to produce PCB's of excellent quality with traces as small as one hundredth of an inch. There are of course minor flaws but all boards are operationally sound. I am willing to produce PCB's for all LMRians for very, very low prices, and circuit test and a microscope evaluation of the board. I can even solder on any SMD components if needed. I guess what this forum is about, is ideas for PCBs for LMR'ians. I have created a couple boards already that I can post, such as a couple PIC controller boards, a Motor Control board and a Li-Ion battery charger board.

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I propose a few boards I always wanted to do but never got to actually do it:

- IR proximity sensor, see OddBot's design, make it with a mounting hole and 3 pin servo style cable

- ATtiny84 LCD backpack with open source firmware

- single channel (reflective IR?) encoder sensors, 3 pin cable

- 2 channel encoders, 4 pin cable

encoder boards will be very simple, the lcd backpack will take some planning, but enlighten me on the proximity sensor, do you have a link?

so far I have the motor board complete, and i can always add indicator leds to it to show the polarities. 

Here is a link to the LCD backpack I was following to modd it to get rid of the keypad and add serial besides I2C, selectable by some jumper: http://john.crouchley.com/blog/archives/612 After lookig again, I see that it uses a Tiny2313 not a Tiny84 as I had in mind, which is cool, as 2313 has both hardware serial and USI, 84 has only USI.

And here is the link to OddBot's proximity sensor: http://letsmakerobots.com/node/2907

 

I wanted to use some ATtiny2313 but I have read through datasheets that ATmega's implementation of serial communications is better (I hope I am not mistaken - I dont remember now the differences). However, I have beeing able to buy cheaper Atmega168A from Farnell than ATtiny2313 from Romania :)

A LCD backpack based on ATmega168A would give more flexibility (having more memory and better hardware) especially if the unused pins would go to a header. One can put an Arduino bootloader on ATmega and having a header for a common USB/serial convertor will be a plus.

A nice design will be a board smaller then the standard LCD and with a header for direct plug in of a LCD

You may be right about using a Mega168 may be better and perhaps cheaper. At the time I was looking into this, there were almost no affordable I2C LCDs around, that changed... I would like to have a LCD+backpack for about $10-15. There are sources for cheap 2x16 LCDs, all I need is the backpack. I thought to have both serial and I2C because I can connect it to a FTDI and print from the computer, or have it plugged all the time in an Arduino board (using I2C), even when uploading code. Of course, we can use software serial, but it sometimes interferes with ohter libraries. Yes, ATmega168 or even a Mega8 should work fine, if they are available easier.

My lcd+backpack I used for my controller http://letsmakerobots.com/node/27429 falls right into that price point. It uses an Arduino, has a FTDI port, I2C breakout, and digital pin 9 and 10 broken out for use with the newsoftserial library and of course has some power and gnd pins around. It also has a pot for adjusting the contrast. Not saying it is in the perfect state, but it could do what you say right now.

...a year ago, so I may rewrite the code for ATmega168 in Arduino (the one for Atmega8 is in assembly and USART only) but my biggest problem was choosing the command set.

Tell me if you are interested, we can talk about the commands and other details.

OddBot said that the design you pointed is deprecated - see his comment.

For cr2 I have made some tests, and tried to amplify the received signal using a BJT - I've got a better range but inconsistent and somehow eratic results. A good design is the simple one, like the OddBot used for compound eye and like I have used for cr2.

As I recall Fritz was looking for and ardiuino board for the start here robot. A board that would have all the IO for motors and sensors. Something like that would be nice.

The guibot's motoruino is like that: http://letsmakerobots.com/node/26745

A LMR special edition would be cool :P